Rotary disc regenerator

Abstract

Rotary disc regenerator, and regenerative air-cooled gas turbine engines embodying the same, characterized by non-rubbing seals which are effective to minimize air-to-exhaust leakage and make it possible to employ a sheet metal matrix as the heat exchange means of the regenerator.

What is claimed is: 
     
       1. In a rotary heat exchanger, useful as a regenerator for gas turbine engines, the combination of a rotary disc comprising: hub means at the center of the disc and having an outer surface which is of outwardly convex radial cross-sectional shape,   an annular member forming the outer periphery of the disc and having an inner surface of inwardly convex radial cross-sectional shape, and   a heat exchange matrix comprising two elongated thin metal sheets each having a width equal to the axial thickness of the matrix, one of said sheets being transversely corrugated and the other being uncorrugated, said sheets being disposed in mutual face-to-face engagement and arranged in a closed   spiral which is concentric with the axis of rotation and in which the uncovered crests of the corrugations of said one sheet in each convolution of the spiral are in contact with said other sheet in the next adjacent convolution of the spiral, the edges of said sheets at each side of the disc lying in a common plane and constituting the face of the matrix,   said spiral having an effective radial thickness such as to completely fill the annular space between said hub means and said annular member,   the inner and outer surfaces of said matrix being generally right cylindrical when the matrix is cool and undistorted,   the central portions of the inner and outer surfaces of said matrix being affixed to the central portions of said outer surface of said hub means and said inner surface of said annular member, respectively; and a stationary seal device disposed adjacent one of the faces of the matrix constituted by the edges of said sheets, said seal device being constructed and arranged to enclose an air flow space through which air under pressure can be supplied to the matrix in a direction parallel to the axis of rotation of the disc, said seal device comprising:     bimetal means extending at least generally along a diameter of the matrix in close proximity to but out of contact with said one face, said bimetal means being operative to wrap the seal device in conformity to said one face of the matrix as the matrix warps under the influence of temperature changes, whereby close proximity of the seal device to the matrix is preserved and rubbing of the matrix against the seal device is avoided.   
     
     
       2. The combination defined in claim 1, and further comprising: a stationary ring located at the end of said hub means which is adjacent said one flat face of said matrix, said bimetal means comprising at least one bimetal bar secured to said ring and extending outwardly therefrom; and     anti-friction means carried by the outer end of said at least one bimetal bar and bearing against the adjacent end of said annular member.   
     
     
       3. In a rotary heat exchanger useful as a regenerator for gas turbine engines, the combination of a rotary disc comprising: hub means located at the center of the disc and having an outer surface which is of outwardly convex radial cross-sectional shape, an annular member forming the outer periphery of the disc and having an inner surface of inwardly convex radial cross-sectional shape, and   an integrated axial through flow heat exchange matrix which, when cool and undistorted, has generally right cylindrical inner and outer peripheral surfaces and two circular major faces which are flat and lie in planes transverse to the axis of rotation of the disc, said matrix defining heat exchange passages extending from one of said major faces to the other and through which gas can flow in heat exchange relation to the matrix,   said matrix, when cool and undistorted, having an effective thickness, in a plane intermediate said major faces, such as to completely fill the annular space between said hub means and said annular member in said intermediate plane, the intermediate portions of said inner and outer surfaces of said matrix being affixed to the intermediate portions of said outer surface of said hub means and said inner surface of said annular member, respectively,   said matrix, when heated, expanding radially in the portions thereof adjacent said major faces, with space for such expansion being afforded by the fact that the radial distance between said onvex surfaces increases from said intermediate portions toward said major faces, such expansion being accompanied by a corresponding bowing of said major faces; and     a stationary seal device mounted adjacent one of said major faces of said matrix, said seal device being constructed and arranged to enclose a gas flow space through which gas under pressure can be supplied to the matrix in a direction parallel to the axis of rotation of said disc, said seal device comprising: bimetal means extending at least generally along a diameter of the matrix in close proximity to but out of contact with said one major face,   said bimetal means being operative to warp the seal device in conformity to said one major face of said matrix as that face warps under the influence of temperature changes, whereby close proximity of the seal device to said one major face of the matrix is preserved and rubbing of the matrix against the seal device is avoided.     
     
     
       4. The combination defined in claim 3, wherein: said hub means has an annular end face adjacent said one major face of said matrix; and   said annular member forming the outer periphery of the disc has an annular end face adjacent said one major face of said matrix,   the combination further comprising: a ring located adjacent said end face of said hub means, said ringbeing concentric with the axis of rotation of the disc; and   stationary means supporting said ring independently with respect to the rotary disc,   said bimetal means comprising at least one bimetal bar secured to said ring and extending outwardly therefrom to a location adjacent said end face of said annular member forming the outer periphery of the disc.     
     
     
       5. The combination defined in claim 4, wherein: said bimetal means comprises two bimetal bars each secured at one end to said ringe, said two bimetal bars divering outwardly from each other; and     said seal device further comprises: an arcuate outer member disposed adjacent said end face of said annular member forming the outer periphery of the disc,   the outer ends of said two bimetal bars being connected to said arcuate outer member, and the combination of said bars, said ring and said arcuate outer member being interconnected as a unit defining a gas flow space.     
     
     
       6. The combination defined in claim 5, wherein said seal device further comprises: roller means carried by said arcuate outer member and disposed in rolling engagement with said end face of said annular member forming the outer periphery of the disc.   
     
     
       7. The combination defined in claim 5, and further comprising: a second stationary seal device mounted adjacent said one major face of said matrix in a location spaced from said first-mentioned seal device, said second seal device comprising: two bimetal bars each connected at one end to said ring and extending outwardly therefrom in mutually divergent fashion, and   an arcuate outer member disposed adjacent said end face of said annular member forming the outer periphery of the disc,   the outer ends of the two bimetal bars of said second seal device being connected to said last-mentioned arcuate outer member.     
     
     
       8. The combination defined in claim 7, and further comprising: a stationary shaft on which said jub means is journalled;   a first tutublar member surrounding and closely adjacent said annular member which forms the outer periphery of the disc;   a support plate fixed to said stationary shaft and extending outwardly therefrom generally parallel to and spaced axially from said one major face of said matrix, said seal devices being located between said support plate and said matrix,   said first tubular member being secured to said support plate,   said support plate having two gas inlet openings each alinged with a different one of said seal devices;     a wall member fixed to said stationary shaft and spaced from said support plate on the side thereof opposite said seal devices;   two axiallly distortable tubular members each having one end connected to a different one of said seal devices and the other end fixed to said support plate and communicating with a different one of said gas inlet openings of said support plate; and means for supplying gas under pressure to the space between said support plate and said wall member.     
     
     
       9. The combination defined in claim 8, wherein: said last-mentioned means comprises: a second tubular member generally concentric with and spaced outwardly from said first tubular member, said second tubular member being secured to said support plate;     said wall member being joined at its outer periphery to said second tubular member;   the annular space between said first and second tubular members being in communication with the space between said support plate and said wall member.   
     
     
       10. The combination defined in claim 8, wherein: said hub means comprises a bearing journalled on said stationary shaft,   the combination further comprising: flow means constructed and arranged to receive gas from the space between said support plate and said wall member and to direct that gas in cooling flow relative to said hub means.     
     
     
       11. The combination defined in claim 3, wherein: said hub means has an annular end face adjacent said one major face of the matrix; and   said annular member forming the outer periphery of the disc has an annular end face adjacent said one major face of the matrix,   the combination further comprising   a stationary member disposed adjacent said annular end face of said hub means,   said seal device further including an outer arcuate member located adjacent said end face of said annular member forming the outer periphery of the disc,   said bimetal means comprising a bimetal bar secured to said stationary member and extending outwardly to the location of said outer arcuate member, and   connection means forming part of said seal device and connecting the outer end of said bimetal bar to said outer arcuate member.     
     
     
       12. The combination defined in claim 11, wherein: said outer arcuate member is flat and lies in a plane parallel to and closely adjacent said end face of said annular member forming the outer periphery of the disc; and   said connection means is constructed and arranged to allow relative movement between the outer end of said bar and said outer arcuate member, whereby said outer arcuate member can retain its parallel relationship with said end face during warping of the seal device by said bar.   
     
     
       13. The combination defined in claim 12, wherein: said connection means includes a flat plate extending across the surfaces of said outer arcuate member and said bar on the side thereof opposite the disc, said plate being secured to said outer arcuate member and to said bar.